Patent Document 1 mentioned below is an example of a power supply apparatus that boosts DC voltage by switching in conventional techniques. The power supply apparatus (“power supply system” in the patent document) comprises a first power supply, a voltage converter that converts voltage outputted from the first power supply, a second power supply to which the voltage from the converter is applied, an electric load system that receives voltage from at least one of the voltage converter and the second power supply, and a controller that controls the voltage converter so that when the system is shifted from a first state that output current from the voltage converter is lower than a current value during an ordinary operation to a second state that the output current is recovered, the output voltage from the voltage converter is maintained high at least during a predetermined period.
In the power supply system, an auxiliary system that is comprised of the voltage converter and the load system connected to the first power supply serving as a main power supply and the second power supply is configured. When voltage supplied from the first power supply to the voltage converter is decreased and the output current from the voltage converter is a low current value and then becomes the current value during the ordinary operation, the second power supply is charged by voltage from the voltage converter that is higher than ordinary one. The power supply system has an advantage that the charge amount of the auxiliary system is recovered earlier with a simple configuration.
Patent Document 1: Japanese Patent Application Laid-Open No. 2003-333835